Hi 1exotic.
1. RAW is an unprocessed picture. It means that the camera writes to the card the pixels as the sensor "sees" them, without any post processing. So you can make the processing afterwards using Canon 3rd party software. Post processing includes ISO, WB etc.
2. Where do you take the picture? What are the settings? In Tv mode you set the shutter speed, what speed is the camera set on? If it's very fast and you're shooting a scene which is not bright enough, you will have a black photo.

Hi 1exotic, Tv mode may let you choose the shutter speed, but for a balanced exposure, you'll still need enough light. Even with the aperture wide open and the ISO increased, there may not be enough.

My advice would be to stick with P (Program) mode for the time being. Or use Aperture Priority mode (Av) and open the aperture to its widest setting (smallest f-number). The camera will then select the fastest shutter speed possible under your current conditions. if you wnat a faster shutter still, try increasing the ISO, but be aware your quality will reduce as this goes up.